Property and Equipment (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$ 18,363	$ 9,134
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		(2,135)	(1,688)
Property, Plant and Equipment, Net		16,228	7,446
Capital Leases, Balance Sheet, Assets by Major Class, Net	[1]	0	7
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		4,950	3,584
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		11,802	4,149
Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,280	1,346
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$ 331	$ 55

[1] Included in furniture, fixtures, and equipment above.